Improvement in fire-alarms



UNITED STATES PATENT OFFICE.

ALBERT F. EELLS, OF BOSTON, MASSAOHUSETTS,'ASSIGNOR OF ONE-HALF HIS RIGHT TO W. H. DOLE AND F. B. DOLE, OF SAME PLACE.

IMPROVEMENT IN FIRE-ALARMS.

Specification forming part of Letters Patent No. 181,323, dated August 22, 1876; application filed July 28, 1876.

To all whom it may concern:

Be it known that I, ALBERT F. EELLs, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Fire-Alarms, of which the following is a specification:

The nature of my invention consists in placing, in different apartments of a building or ship, a series of air-chambers, eachchamber being connected by a suitable tube to a reservoir of mercury so arranged that when the air in any of the chambers becomes dilated by heat, it will force the mercury out of the reservoir, and into a counterpoise-cup attached to a let-oft device of an alarm. Thus any excess of heat in any apartment will cause an alarm to be sounded, and thus give warning of danger.

Figure 1 is a perspective view of the invention, showing two air-chambers. Fig. 2 is a detail of a part of the let-off device.

Let A represent a board or wall, to which the alarm device is attached. 0 and D represent air-chambers, one of which may be lo cated in each of the apartments from which it is desirable to communicate. and D are tubes connecting the air-chambers with the mercury-reservoirs, one of which is shown at 0 Each mercury -reservoir consists of a siphon and bulb, as shown, one arm of the siphon being connected with the pipe or tube from the air-chamber, while the other end 0 is open, and delivers into a tunnel-shaped receiver, E. H H is a tube leading from the lower part of the receiver E down to the counterpoise-cup K.

From the above description it may be seen that in case the confined air in the chamber 0 is dilated by heat it will act, through the tube 0 upon the mercury in the bulb O and, forcing it up through the tube 0, will cause it to overflow into the receiving tunnel E, from which it will run down the tube H, and into the counterpoise K. The counterpoise K acts upon the let-0ft device in the following manner: The counterpoise-cup K is attached to a tilting lever, K and balanced by a Weight, K Intermediate between the parts K and K the lever is pivoted and attached to a crank, K. The object of the crank K is to hold the end of the let-off lever L. (See Figs. 1 and 2.) The lower end of the lever L is connected to the pallet M, and is so arranged, in connection with the escapement-wheel M, that when the lever L is held back by the crank K the wheel M cannot turn; but when the lever L is released, as it will be when the counterpoise-cup K is full of' mercury, by the dropping of that end of the lever K then the pallet M can freely vibrate, and allow the alarm mechanism T to operate. This mechanism acts through the hammer R upon the bell P, and gives the alarm. The ascending arms D O of the siphons may be marked to show with which apartment it is connected, so that the particular apartment from which the signal comes may-be indicated.

I claim as my invention- 1. The combination of the air-chambers (J, &c., with the mercury-reservoirs and the counterpoise-cup K, all operatin g substantially as described, and for the purpose set forth.

2. The combination of the counterpoise-cup K, the lever K crank K and let-off device L M, with the alarm device T, all operating together substantially as described, and for the purpose set forth.

ALBERT F. EELLS. 

